Natural polyamines, e.g., spermidine, norspermidine, homospermidine, 1,4-diaminobutane (putrescine), and spermine, are simple aliphatic amines produced in eukaryotic cells by a highly regulated metabolic apparatus. Polyamine levels and the activity of the polyamine biosynthetic apparatus tend to be high in dividing mammalian cells and low in quiescent cells. Populations of cells depleted of their polyamine content stop growing and may die. Janne et al. (1978) A. Biochim. Biophys. Acta. 473:241 and Pegg et al. (1982) Am. J. Cell. Physiol. 243:212–221. Polyamines are reviewed in Morgan (1998) Methods. Mol. Biol. 79:3–30.
Several lines of evidence indicate that polyamines, particularly spermidine, are required for cell proliferation: (i) they are found in greater amounts in growing than in non-growing tissues; (ii) prokaryotic and eukaryotic mutants deficient in polyamine biosynthesis are auxotrophic for polyamines; and (iii) inhibitors specific for polyamine biosynthesis also inhibit cell growth. Despite this evidence, the precise biological role of polyamines in cell proliferation is uncertain. It has been suggested that polyamines, by virtue of their charged nature under physiological conditions and their conformational flexibility, might serve to stabilize macromolecules, such as nucleic acids, by anion neutralization. Hafner et al. (1979) J. Biol. Chem. 254:12419; Pohjatipelto et al. (1981) Nature 293:475; Mamont et al. (1978) Biochem. Biophys. Res. Commun. 81:58; Bloomfield et al. (1981) in Polyamines in Biology and Medicine, Morris et al., Eds., Dekker, New York, pp. 183–205.
A treatment approach has been devised based on the observation that increases in the polyamine pool suppress polyamine biosynthesis. Porter et al. (1988) in Advances in Enzyme Regulation, Pergamon Press, pp. 57–79. This approach attempts to identify polyamine analogs which down-regulate polyamine biosynthesis, but which do not perform the polyamine functions required for cell growth. BESPM, a N-bis(ethyl) analog of spermine, has served as a model compound for this strategy. BESPM rapidly suppresses polyamine biosynthetic enzymes, depletes natural polyamine pools, and inhibits cell growth in vitro. Porter et al. (1987) Cancer Res. 47:2821–2825. In addition, BESPM suppresses polyamine uptake (Byers et al. (1990) J. Physiol. 142:460–467; and Kramer et al. (1993) J. Cell. Physiol. 115:399–407), and thus minimizes the ability of tumor cells to meet their polyamine requirement by taking them up from their environment. BESPM and related analogs also induce the polyamine metabolizing enzyme spermidine/spermine N1-acetyltransferase (SSAT) in certain human carcinoma cell lines.
BESPM and other polyamine analogs have been used, or proposed for use, in treating a large variety of diseases, including a number of different cancers. U.S. Pat. No. 5,541,230. Polyamine analogs demonstrated, for example, potent antitumor activity against several melanoma cell lines and tumors in vitro (Porter et al. (1991) Cancer Res. 51:3715–3720; Shappell et al. (1992) Anticancer Res. 12:1083–1090) and in vivo using tumors growing as xenografts in athymic mice (Bernacki et al. (1992) Cancer Res. 52:2424–2430; Porter et al. (1993) Cancer Res. 53:581–586). Potent antitumor activity of bis-ethyl spermine analogs has also been demonstrated for pancreatic cancer cell lines in vitro (Chang et al. (1992) Cancer Chemother. Pharmacol. 30:183–188) and in vivo (Chang et al. (1992) Cancer Chemother. Pharmacol. 30:179–182). Polyamine analogs have also been suggested for use in treating brain tumor therapy. Redgate et al. (1995) J. Neurooncol. 25:167–79. In addition to being useful against cancers of the brain, pancreas, and skin, polyamine analogs are also useful against cancers of the bladder, bone, breast, colon, digestive tract, lung and ovaries. Chang et al. (1993) J. Urol. 150:1293–7; Snyder et al. (1994) Anticancer Res. 14:347–56; Yuan et al. (1994) Biochem. Pharmacol. 47:1587–92; Davidson et al. (1993) Cancer Res. 53:2071–5; Berchtold et al. (1998) J. Cell. Physiol. 174:380–6; Porter et al. (1988) Adv. Exp. Med. Biol. 250:677–90; U.S. Pat. Nos. 5,498,522 and 5,374,658. U.S. Pat. No. 5,498,522 presents the use of spermidine/spermine N1-acetyltransferase as a prognostic indicator of the efficacy of a polyamine analog against a malignant tumor.
Polyamine analogs have been used to treat cancer of the prostate. Mi et al. (1988) Prostate 34:51–60. Polyamines are produced in large amounts by the prostate gland and are abundant in the seminal fluid. Herr et al. (1984) Cancer 53:1294–8. Polyamine analogs such as BE-4444, BE-373, and BE-333 are particularly effective in inhibiting prostate xenograft tumors in nude mice. Zagaja et al. (1998) Cancer Chem. Pharm. 41:505–512; Jeffers et al. (1997) Cancer Chem. Pharm. 40:172–179; Feuerstein et al. (1991) J. Cell. Biochem. 46:37–47; and Marton et al. (1995) Ann. Rev. Pharm. Toxicol. 35:55–91.
In addition to treating cancer, polyamines and their analogs have uses in treating a number of other diseases and in numerous other medicinal applications. Oxidized polyamines are believed to inhibit growth of parasites (Morgan et al. (1983) Adv. Polyamine Res. 4: 169–174; Morgan et al. (1986) Biochem. J. 236:97–101; and U.S. Pat. No. 4,935,449) and suppress infectivity of selected strains of bacteria and fungi (Bachrach et al. (1971) J. Gen. Virol. 13:415–22; Nishimura et al. (1971) Biochim. Biophys. Acta 247:153–6; and U.S. Pat. No. 5,744,453). Polyamines such as spermine and polyamine analogs are also anti-viral and some are anti-insecticidal. Bachrach et al. (1972) Appl. Microbiol. 23:232–5; Bachrach et al. (1971) J. Gen. Virol. 11:1–9; U.S. Pat. Nos. 5,021,409; 5,606,053; 5,608,061; 5,612,478; and 5,681,837. In addition, oxidized polyamines, such as spermine dialdehyde, for example, can be used in treatment of tissue grafts and other organs for transplantation. U.S. Pat. No. 5,374,658. Polyamine analogs can also be used to treat neurodegenerative diseases and neurotrauma such as stroke. U.S. Pat. Nos. 5,646,188 and 5,677,349. Polyamine analogs have also been reported to be useful as anti-psoratic agents, and in the treatment of epilepsy, Alzheimer's disease, and multiple sclerosis, as described in U.S. Pat. No. 5,646,188. Polyamine analogs are also useful in treating and preventing restenosis. U.S. Pat. No. 5,516,807. Polyamine analogs are also useful in treatment of gastric ulcers. Igarashi et al. (1990) Biochem. Biophys. Res. Commun. 172:715–20. In addition, polyamine derivatives including N-alkythio polyamine derivatives, polyamine thiols, and polyamine phenols are useful as radioprotective agents for normal tissues during radiotherapy. U.S. Pat. Nos. 5,217,964; 5,354,782; and 5,434,145.
Polyamines and their analogs can be administered alone or in conjunction with additional agents. For example, therapeutic polyamines can be administered along with 1,3-bis (2-chloroethyl)-1-nitrosourea. U.S. Pat. No. 5,541,230. In treating cancer, polyamines can be co-administered with various cytotoxic agents, including antineoplastic vinca alkaloids, antibiotics, antimetabolites, and platinum coordination complexes. U.S. Pat. No. 5,654,287.
In addition to the various aforementioned medicinal uses, polyamines and polyamine analogs have a variety of industrial uses, including derivativization of silica. U.S. Pat. No. 5,763,388. Polyamines have also been used in conjunction with other clarification aids to treat wastewaters. U.S. Pat. Nos. 5,413,719 and 5,707,532. The combination of aluminum chlorohydrate and a polyamine is an effective emulsion breaker for reverse (oil-in-water) emulsions, e.g. in a matrix comprising mostly oil as encountered in a crude oil desalter unit. U.S. Pat. No. 5,607,574. Polyamines are also useful in deodorizing polysulfides. U.S. S.I.R. H1,633. Polyamines are also used in industrial dyes. U.S. Pat. No. 5,672,202. Polyamines and hot water can also be used in manufacturing microcapsules. U.S. Pat. No. 5,401,443. The antioxidative and metal-chelating effects of polyamines are reviewed in Lovaas (1997) Adv. Pharmacol. 38:119–149.
It would be advantageous to develop novel polyamine analogs for various uses, including disease treatment.
All references cited herein are hereby incorporated by reference in their entirety.